linux/include/net/pkt_sched.h
Vlad Buslov 3a7d0d07a3 net: sched: extend Qdisc with rcu
Currently, Qdisc API functions assume that users have rtnl lock taken. To
implement rtnl unlocked classifiers update interface, Qdisc API must be
extended with functions that do not require rtnl lock.

Extend Qdisc structure with rcu. Implement special version of put function
qdisc_put_unlocked() that is called without rtnl lock taken. This function
only takes rtnl lock if Qdisc reference counter reached zero and is
intended to be used as optimization.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-25 20:17:35 -07:00

165 lines
4.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __NET_PKT_SCHED_H
#define __NET_PKT_SCHED_H
#include <linux/jiffies.h>
#include <linux/ktime.h>
#include <linux/if_vlan.h>
#include <linux/netdevice.h>
#include <net/sch_generic.h>
#include <net/net_namespace.h>
#include <uapi/linux/pkt_sched.h>
#define DEFAULT_TX_QUEUE_LEN 1000
struct qdisc_walker {
int stop;
int skip;
int count;
int (*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
};
#define QDISC_ALIGNTO 64
#define QDISC_ALIGN(len) (((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
static inline void *qdisc_priv(struct Qdisc *q)
{
return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
}
/*
Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
Normal IP packet size ~ 512byte, hence:
0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
10Mbit ethernet.
10msec resolution -> <50Kbit/sec.
The result: [34]86 is not good choice for QoS router :-(
The things are not so bad, because we may use artificial
clock evaluated by integration of network data flow
in the most critical places.
*/
typedef u64 psched_time_t;
typedef long psched_tdiff_t;
/* Avoid doing 64 bit divide */
#define PSCHED_SHIFT 6
#define PSCHED_TICKS2NS(x) ((s64)(x) << PSCHED_SHIFT)
#define PSCHED_NS2TICKS(x) ((x) >> PSCHED_SHIFT)
#define PSCHED_TICKS_PER_SEC PSCHED_NS2TICKS(NSEC_PER_SEC)
#define PSCHED_PASTPERFECT 0
static inline psched_time_t psched_get_time(void)
{
return PSCHED_NS2TICKS(ktime_get_ns());
}
static inline psched_tdiff_t
psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
{
return min(tv1 - tv2, bound);
}
struct qdisc_watchdog {
u64 last_expires;
struct hrtimer timer;
struct Qdisc *qdisc;
};
void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
clockid_t clockid);
void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires);
static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
psched_time_t expires)
{
qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
}
void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
extern struct Qdisc_ops pfifo_qdisc_ops;
extern struct Qdisc_ops bfifo_qdisc_ops;
extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
int fifo_set_limit(struct Qdisc *q, unsigned int limit);
struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
unsigned int limit,
struct netlink_ext_ack *extack);
int register_qdisc(struct Qdisc_ops *qops);
int unregister_qdisc(struct Qdisc_ops *qops);
void qdisc_get_default(char *id, size_t len);
int qdisc_set_default(const char *id);
void qdisc_hash_add(struct Qdisc *q, bool invisible);
void qdisc_hash_del(struct Qdisc *q);
struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle);
struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
struct nlattr *tab,
struct netlink_ext_ack *extack);
void qdisc_put_rtab(struct qdisc_rate_table *tab);
void qdisc_put_stab(struct qdisc_size_table *tab);
void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
struct net_device *dev, struct netdev_queue *txq,
spinlock_t *root_lock, bool validate);
void __qdisc_run(struct Qdisc *q);
static inline void qdisc_run(struct Qdisc *q)
{
if (qdisc_run_begin(q)) {
__qdisc_run(q);
qdisc_run_end(q);
}
}
static inline __be16 tc_skb_protocol(const struct sk_buff *skb)
{
/* We need to take extra care in case the skb came via
* vlan accelerated path. In that case, use skb->vlan_proto
* as the original vlan header was already stripped.
*/
if (skb_vlan_tag_present(skb))
return skb->vlan_proto;
return skb->protocol;
}
/* Calculate maximal size of packet seen by hard_start_xmit
routine of this device.
*/
static inline unsigned int psched_mtu(const struct net_device *dev)
{
return dev->mtu + dev->hard_header_len;
}
static inline struct net *qdisc_net(struct Qdisc *q)
{
return dev_net(q->dev_queue->dev);
}
struct tc_cbs_qopt_offload {
u8 enable;
s32 queue;
s32 hicredit;
s32 locredit;
s32 idleslope;
s32 sendslope;
};
struct tc_etf_qopt_offload {
u8 enable;
s32 queue;
};
#endif